Electrical outlet terminal



Jan. 25,v 1949;

B. P. MOKINLEY ELECTRICAL ouTLET `TERMINAL FiledJan. 29, 1945 Patented Jan. 25, 1949 UNITED STATES PATENT OFFICE 2,459,832 ELECTRICAL OUTLET TERMINAL Benjamin P. McKinley, Bradenton, Fla. Application January 29, 1945, Serial No. 575,115

Claims.

This invention relates to improvements in electrical apparatus.

One object of the invention is to provide an improved electrical terminal for use in outlet receptacles or in attachment plugs.

Another object of the invention is to provide a terminal formed of a conductor material shaped to provide one of a pair of contact members as well as conductor receiving and anchoring means.

An additional object of the invention is to provide an electrical terminal that can be manufactured economically from strip material by dieforming operations and which includes means providing a relatively large contact-area, solderless connection for a conductor, and is provided with means for anchoring the conductor Within the terminal firmly against accidental dislodgement.

Another object of the invention is to provide electrical terminals and an insulating receptacle therefor into which the terminals may-be in-4 serted and retained in positions of `use by a common closure and without employing individual securing means for the terminals.

Other objects of the invention relate to various features of construction and arrangement of parts which will be apparent from a consideration of the following specification and accompanying drawings wherein:

Figure 1 is an elevation of a conventional outlet box, and a cover therefor, and a receptacle provided with electrical terminals which are illus'- trative of the present improvements;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a rear end view of a receptacle, detached from the box of Fig. 1 showing three terminals in position therein;

Fig. 4 is an enlarged broken side elevation of a detached terminal illustrating a conductor and conductor anchoring means in position therein;

Fig. 5 is a partial side elevation of a terminal with the conductor anchoring means removed;

Fig. 6 is a sectional view taken on line 6-6 of Fig. 4;

Fig. 7 is an end elevation looking inthe direction of arrows 'I-'I of Fig. 5,

Fig. 8 is a side elevation of a terminal embodying the invention for use with one or more others in a plug cap.

In the drawings, the improved apparatus shown for illustrative purposes comprises a conventional outlet box I0 that may be installed in a wall or in any position where the outlet is to be single length of strip present disclosure three such cells are used. A box cover II is shown that maybe conventional except that it is provided with an opening corresponding to the cross-sectional shape of the rear portion of an insulating receptacle I2, the rear portion being formed of the shape required in providing terminal cells I3. In the shown, the receptacle being designed for a three-Wire circuit such as generally is employed for electric ranges for example. Where other than a three wire system is employed, the receptacle isv provided with the number of cells for the required terminals.

An improved terminal, the numeral I`4 is shown in Figs. 4 and 5 detached from the receptacle and as therein shown is formed of a strip of suitable conductive metal or alloy. The terminal is of such shape as to provide novel advantages in use and such that it can be die-formed for economy in production and requires no mounting as distinguished from mere placement and confinement within a cell I3. The assembly of the improved apparatus, including the terminals and receptacle, is thereby simplied over the assembly of present terminals that generally are attached to a base, as by screws or rivets or are formed integral with a base that requires mounting on an insulating indicated generally by support.

The strip' of which the improved terminal is formed is shaped, as by die-forming operations, to provide a pair of arms I5 which at one end of the terminal are turned inwardly, to provide a.` The cooperating pair of contact members I6. pair of contacts I6 are slightly spaced apart as indicated at I6a, and provide electrical contact with an inserted male member of a terminal plug, such as is shown in Fig. 8, and later described. The member I4 is thus the `female of a pair of cooperating circuit connectors, the arms I5 being suiciently resilient to enable them to spring apart in receiving therebetween a blade such as that above mentioned.

At the other end of the terminal the strip is provided with a reentrant portion that isl disposed between the arms andis indicated generally by numeral I1. Portion I'I is formed to provide a longitudinal passage I'8 that is threaded to receive a screw I9 having a tapered or conical inner end 20 as shown in Fig. 4. The portion I'I is provided also with a transverse passage 2| that intersects the axial passage I8 and preferably is of somewhat smaller diameter than passage I8 whereby there are formed two opposed concavities 22 in the wall ofthe transverse passage. An end of a conductor 23 forming part of a current carrying cable is adapted to be inserted in the transverse passage 2|, the diameter of the passage preferably being but slightly greater than the diameter of the conductor.

Conductors employed in connecting outlet receptacles to a source of current supply generally are of the stranded type and where the stranded end of such a .conductor is inserted in a passage 2| and the screw I9 is thereafter tightened upon the conductor, the strands 23a of the conductor within the passage 2| are divided or separated at the intersection of the `passages and are pressed nrmly in contact with the walls of the passage 2| to provide a`relatively large area, solderless electrical connection. The separation or division of the strands by the screw, I9 deforms a part of the strands into the concavities 22 and thereby further ilrmly anchors the conductors within the passage against displacement.

For the purpose of preventing the springing apart of the halves of the reentrant portion I1 along the plane of Vtheir contacting faces, they preferably are made integral at the inner ends as indicated at 2l, while the contacting edges of the halves at the other end of the terminal are secured together as by welding, asv indicated at 25. Such arrangement provides rigid screw holdingv and conductor holding passages that do not expand or deiorm under .the action of the screw as the latter is turned inwardly in providing ilrm and close electrical contact between the bared end of a conductor 23 and the wall of the recess 2 I.

The inner end 24 of the reentrant portion is The improved terminal above described is of the female type but a male type, such as is shown in' Fig. 8 may be made in accordance lwith the principle of the invention. In Fig. 8 parts common to those shown in Fig. 4 and indicated by Vsimilar reference characters, the difference beshown provided with a drilled or otherwise formed recess 26 for receiving the point or` apex of the screw I9 should the latter be screwed inwardly suiliciently to require accommodation beyond the wall of the transverse passage 2|.

As indicated in Figs. l, 2 and 3, terminals of the type described above are adapted to be positioned within the cells I3 of the receptacle II. Each cell is provided with a conductor opening 21 that is in alignment with the conductor passage 2| of the respective terminal whereby after a terminal I4 has been positioned properly within a cell, a bared end of a conductor can be inserted through the opening 21 into the passage 2 Il of the terminal and secured firmly in place by tightening down the screw I9, as above described.

The positioning of the terminals in the cells as to cause the transverse passages 2| of the terminals to register with the openings 21 of the cells, effects proper alignment of the space Isa between the contact portions IB of each terminal with a slot or opening 28 provided in the forward external portion I2a of the insulating receptacle I2. Hence insertion of blades of an outlet plug into the openings 28 insures electrical connection as between the terminals and the blades.

For the purpose of securing the terminals within the cells, an insulating closure member is provided which, in the form illustrated, comprises an insulating disc 29 which is secured over the rear ends of the cells by means of a, bolt 30 provided with a nut 3| at the rear thereof. The terminals are thus merely confined within the cells, as distinguished from being mounted upon bases by screws or vrivets as has been common heretofore. An economical structure as wellas one that can be assembled readily is provided by the improvements disclosed.

In Fig. 2 the outlet box III is shown with a knock-out opening through which a cable 32 comtween the two forms residing in shaping the arms I5 to provide a single terminal blade 34. The required number oi such male terminals may be mounted in a plug cap or equivalent insulating support, not shownfthe blades Il of which are so spaced and-disposed in planes as to enable them to be pressed through the slots 28 into electrical contact between the contact arms I8 of the female terminals I4. The arms I5 ofthe member shown in Fig. 8 are attached together adjacent their forward ends, as by welding, as indicated at 35.

In the forms of the improvements illustrated, the anchoring screw Il is shown disposed within the axial passage of the terminal and the conductor within the transverse passage, although use of the reverse arrangement is contemplated where advantageous.

While I have shown and described a structure illustrative of the invention it will be seen that changes in detail thereof may be made within the'scope of the invention deilned by the following claims.

I claim:

l. An electrical terminal comprising a strip of conductive metal shaped to provide a contactV means at one end and providing a pair of spaced apart arms having a reentrant portion extending inwardly between the arms at the other end of the terminal defining an axial passage and a transverse `passage intersecting said axial passage, and conductor anchoring means in one of said passages adapted to engage a conductor end inserted in the other of said passages.

2. An. electrical terminal comprising a strip of conductive metal shaped to provide contact means at one end and providing a pair of spaced apart arms having a reentrant portion at the other end -disposed between said arms and providing an axial passage and a transverse passage intersecting said axial passage, one of said passages being of greater diameter than the other to provide opposed concavities in the walls of the smaller passage, and conductor anchoring means in saidlarger passage adapted to separate the stranded end portion of a conductor inserted into the smaller passage and to deform some of the strands into said concavities for anchoring the conductor within said smaller passage in ilrm electrical contact with the wall thereof.

3. An electrical terminal comprising a strip of conductive metal shaped to provide contact means at one end and providing a pair of spaced apart .arms having a common reentrant portion at the other end disposed between said arms and providing an axial passage and a transverse passage intersecting said axial passage, said axial passage being of greater diameter than said transverse passage to provide opposed concavities in the walls of said transverse passage and being threaded for receiving a set screw, and a set screw for :incassaA verse passage and to press the portions of thestrands into firm electrical contact with the walls of the transverse passage and to deform some of said strands into said concavities for anchoring the conductor rmly within said last mentioned passage.

4. An electrical terminal comprising a strlpof conductive material shaped to provide contact means at one end of the terminal anda pair of spaced apart arms having inwardly directed portions at the other end of the terminal, said portions being connected at the inner ends thereof and being complementarily shaped to provide an axial passage and a transverse passage intersect ing said axial passage between said arms, means connecting said complementary portions together at the edges adjacent said last mentioned end of the terminal to prevent separation of said portions, and a member for said axial passage forv engaging a conductor end inserted into said transverse passage and pressing the same into rm electrical contact with the wall of said transverse passage. Y

5. An electrical terminal comprisingaEstrip of conductive material shaped to provide contact means at one end of the terminal and a pair of spaced apart arms having inwardly' directed portions at the other end o f the terminal, said portions being integrally united at the inner ends 20 Number Name Date 1,522,022 Meier Jan. 6, 1925 1,994,880 Wallbillich Mar. 19, 1935 2,043,512 Hoover June 9, 1936 2,162,545 Benander et al. June'13, 1939 25 2,176,137 Jurkat Oct. 17, 1939 2,358,745 Stieglitz Sept. 19, 1 944 2,371,446 Jensen Mar. 13, 1945 2,374,107 Langford Apr. 17, 1945 FOREIGN PATENTS so Number Country Date 418,244 Great Britain May 16, 1934 thereof and being complementarily shaped to provide an axial passage-and a transverse passage intersecting said axial passage between said arms, an operable member within said axial passage for engaging a conductor and inserted into said transversepassage and pressing the same into firm electrical contact with the wall of said transverse passage, and means at the outer ends of said portions for preventing separation thereof by said operable member Within said axial passage.

BENJAMIN P. MCKINLEY.

y REFERENCES I CITED UNITED STATES PATENTS Certificate of Correction Patent No. 2,459,832. January 25, 1949.

BENJAMIN P. MCKINLEY 1,4 It is hereby certified that error appears in the printed specification of the ebove numbered patent requiring correction as follows:

Column 6, line 5, for the Words conductor and reed conductor end;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case 1n the Patent Office.

Signed and sealed this 13th day of September, A. D. 1949.

[SEAL] IJOE E. DANIELS,

.daszstant Oanunflssz'oner of Patents. 

